Evaluate effects of LHRH antagonists on normal men. Administered the LHRH antagonist, "Nal-Glu" as a daily subcutaneous injection of 5mg for 21 days. Serum levels of immunoreactive FSH, LH, testosterone (T), "Nal-Glu" (Radioreceptor assay) and bioactive LH were measured daily during a 3-day baseline period, during the antagonist administration and a follow-up period.